Is one dose of human papillomavirus vaccine as effective as three?: A national cohort analysis

Prophylactic human papillomavirus (HPV) vaccines are highly effective at preventing pre–cancerous cervical lesions when given in a three–dose schedule. Some post–hoc trial data suggest that one dose prevents HPV infection. If one dose could prevent pre–cancerous cervical lesions, then global cervical cancer prevention would be greatly facilitated. We assessed the effectiveness of quadrivalent HPV vaccine by number of doses against cervical intraepithelial neoplasia (CIN) 2 or 3/adenocarcinoma–in–situ (AIS)/cancer in Australia up to seven years post vaccination